JComboBox宽度 [英] JComboBox width

问题描述

我创建了一个jComboBox，但它占用了帧的全宽。如何设置宽度固定。

I have created a jComboBox but it takes the full width of the frame. how to set the width fixed.

是面板的框架和框布局的borderlayout。我在这里添加代码：

yes borderlayout for the frame and box layout for the panel. i am adding the code here:

import javax.swing.*;
import java.awt.BorderLayout;

public class Window8  {

    JFrame frame;
    JPanel panel;
    JComboBox combo;
    public void go(){

    String[] option = { "STUDENT", "TEACHER" };

    combo.setPreferredSize(new Dimension(1,25));
    combo = new JComboBox(option);
    menu.setSelectedIndex(0);

    frame = new JFrame("DELETION"); 
    frame.setLocationRelativeTo(null);
    frame.setSize(400, 300);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setVisible(true);

    panel = new JPanel();
    panel.setLayout(new BoxLayout(panel,BoxLayout.Y_AXIS));

    frame.getContentPane().add(BorderLayout.NORTH,panel);
    panel.add(combo);   
}

推荐答案

宽度自动由添加到组合框的最大项的宽度。您可以使用以下方法控制显示：

The width is automatically determined by the width of the largest item added to the combo box. You can control the display by using:

comboBox.setPrototypeDisplayValue("text here");

您也可以考虑使用组合框弹出窗口来控制弹出窗口大小。

You might also consider using the Combo Box Popup to control the popup size.

编辑：

由于您添加的代码显示您正在使用BoxLayout，因此您可以尝试以下操作：

Since you added code that shows you are using a BoxLayout you can try the following:

comboBox.setMaximumSize( comboBox.getPreferredSize() );

或者你可以这样做：

JPanel wrapper = new JPanel();
wrapper.add( comboBox );
panel.add( wrapper );

阅读使用布局管理器了解这些建议的工作原理。

Read the section from the Swing tutorial on Using Layout Managers to understand how these suggestions work.

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